LGA Component Package

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Overview

A 3D render of an LGA component package.

A 3D render of an LGA component package.

The LGA package is is a surface mount package with pads on the underside of the package. It is very similar to the BGA package, except is does not have any balls, instead plain flat pads are used. An LGA package may also differ from BGA with the addition of arbitrary sized pads for purposes such as grounding, thermal dissipation, shielding and mechanical strength. An LGA package can be made from a PCB, thus many LGA components are actually entire “modules” made from a PCB and a number of components. This modular form is commonly seen with cellular modem and WiFi components.

CPU Variants:

CodeSocket Name
LGA 771Intel Socket J
LGA 775Intel Socket T
LGA 1150Intel Socket H3
LGA 1155Intel Socket H2
LGA 1156Intel Socket H
LGA 1207AMD Socket F, AMD Socket C32
LGA 1356Intel Socket B2
LGA 1366Intel Socket B
LGA 1944AMD Socket G34
LGA 2011Intel Socket R

The LGA package comes in many different variants, all which have a different number of pins and a different pin configuration. The pins are normally lines up in a grid of x columns and y rows, but not every position may have a pad. Therefore you can get variants with the same LGA package width and length.

Cannot solder with a soldering iron, soldering with hot air or infrared is o.k., recommended practise is to use reflow techniques.

Like BGAs, LGA packages can withstand up to 50% mis-alignment when soldering (50% of the distance between consecutive pads, i.e. it’s pitch), as the package will automatically align itself1. LGA packages can be connected to the PCB either with a socket or direct soldering. Intel has popularised the package by using it on some of it’s CPU families.

Socket

Socket for the LGA-775 component package.

Socket for the LGA-775 component package.

Shifted Solder Mask Layouts

Sometimes LGA components recommend unique paste mask designs with “shifted” openings, as shown below.

The recommended paste mask layout (Panasonic labels this the "solder mask", but they are really talking about what most people call the paste mask!) for the Panasonic PAN9026. Notice the unequal shifting of approx. 150um[^bib-panasonic-pan9026-design-guide].

The recommended paste mask layout (Panasonic labels this the “solder mask”, but they are really talking about what most people call the paste mask!) for the Panasonic PAN9026. Notice the unequal shifting of approx. 150um2.

Common Uses

  • CPUs
  • Cellular modems
  • WiFi modules

Similar To

  • BGA: A BGA has balls on the underside pads, while a LGA doesn’t.
  • PGA

References


  1. NXP (2009, Oct). AN3241: Land Grid Array (LGA) Package Rework. Retrieved 2022-04-19, from https://www.nxp.com/docs/en/application-note/AN3241.pdf↩︎

  2. Panasonic. PAN9026: Wi-Fi Dual Band 2.4/5 GHz and Bluetooth Module. Design Guide. Rev. 1.1.. Retrieved 2022-04-19, from https://mediap.industry.panasonic.eu/assets/custom-upload/Devices/Wireless%20Connectivity/Wi-Fi%20Modules/PAN9026/WM%20PAN9026%20Design%20Guide.pdf↩︎


Authors

Geoffrey Hunter

Dude making stuff.

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This work is licensed under a Creative Commons Attribution 4.0 International License .

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